Order your favourite plants early!
Planning your summer garden certainly lifts the spirits when days are short but it's not just psychological, there are practical benefits too. Deciding on ‘must have' plants early in the season means you don't have to worry about them. They'll be grown by expert growers and delivered when weather and soil warms up and at the right time to plant so you won't need to fret about them.
But if you order a lot of plants for baskets and containers it makes sense to plan where to keep them if weather suddenly gets cold. A greenhouse is ideal for growing on young plants prior to planting but if you don't have a greenhouse find your plants a sheltered, well lit spot such as a conservatory or frost free porch to protect them. A bright windowsill can also be a useful spot.
If you plan to grow a lot of hardy plants and young vegetables consider investing in a cold frame. Cold frames are the perfect halfway house between the warm indoors and cool outside so they are really useful for ‘hardening off' young plants prior to planting out. Insulating cold frame lids with bubble wrap will keep plants snug inside if it gets unexpectedly cold.
If you're new to growing; ‘hardening off' just means getting plants used to outdoor temperatures. The easiest way to do this is leave plants exposed to outside temperatures during the day when days are warm, but bringing them under cover at night until all risk of frost has passed. If plants are in a cold frame just open the lids on warm days and close them at night. Some plant foliage can turn colour as they harden off - lobelia foliage will often take on a bronze tinge, this is nothing to worry about and won't affect the plants' performance.
Of course the most important phrase in this explanation is ‘until all risk of frost has passed' None of us has a crystal ball and weather conditions differ depending on which part of the country you are in so be guided by fellow gardeners, personal experience and the weather forecasts. It is normally safe to assume that weather will be frost free by mid May - but June frosts are not unheard of in parts of Scotland. Factor this in and be prepared to use some fleece to protect plants. In an emergency a few sheets of newspaper will work as a temporary 'blanket'.
Ventilation is as important as keeping young plants frost free so try not to keep plants ‘cooped up' in airless, stagnant conditions. Good airflow and careful watering helps to prevent fungal infections such as mildew, leaf spot and botrytis (mould) on plants such as antirrhinums, fuchsias, bedding begonias and pansies.